Learning Redux

Looking at the counter reducer

The counter is controlled by a counterReducer in src/reducers/counter.js:

import { INCREMENT, DECREMENT, RESET } from '../actionTypes'export default function counterReducer (state = 0, action) {  switch (action.type) {

Its logic is quite simple:

• On an INCREMENT action, increase the state by 1:

    case INCREMENT:      return state + 1

• On a DECREMENT action, decrease the state by 1:

    case DECREMENT:      return state - 1

• On a RESET action, set the state to 0:

    case RESET:      return 0

• For unhandled action types, simply return the current state:

    default:      return state  }}